import re

s1 = "19:00-20:00"
s2 = re.findall("\d{1,2}[:]\d{1,2}[-]\d{1,2}[:]\d{1,2}", s1)
print(s2)
#
# str1 = "组织部门：人力资源部"
# substr = "："
#
# print(str1[str1.rfind(substr) + 1:])
